More than a year after Hamas’ devastating October 7 attacks on Israel, the country’s military said Thursday it had killed the man it considers to have been the chief architect of that cross-border incursion – raising questions about the future of the war and of the militant group itself,

In confirming Sinwar’s death — a full day after it was announced by Israel — Hamas said Friday it mourned the loss of a “great leader.” But it voiced defiance, vowing not to return the hostages seized on Oct. 7 of last year to Israel until there is a cease-fire in the Gaza Strip and a withdrawal of Israeli troops.

Sinwar, a U.S.-designated terrorist, is regarded as the architect of Hamas' Oct. 7, 2023, attacks on Israel. The death drew comparisons to the killing of Osama bin Laden.